The 1996 revisions (ASAE 279.10) to ASAE standard 279.9 for the lighting and marking of agricultural equipment when traveling on a highway require that tractors and self-propelled farm equipment must have two amber warning lights, visible from the front and rear, and flashing in unison at a rate of 60 to 85 flashes per minute. Turn signals are required and the amber warning lights must also serve as the turn indicators. When a turn is signaled, the amber light in the direction of the turn must flash and the amber light in the direction opposite the turn must become steady burning. The amber flashing warning lamp in the direction of turn must increase in flashing rate a minimum of 20 flashes per minute, so as to flash at a rate of at least 80 but no greater than 110 flashes per minute. In addition, a red tail lamp or an additional amber lamp must flash in the direction of turn and in unison with the amber flashing warning lamp.
Typically, the signal for energizing the brake lamps on a vehicle is derived from a switch operated either by a brake pedal which is depressed to cause deceleration, or by the increase in pressure in the hydraulic braking system when the brake pedal is depressed. However, some agricultural equipment, such as the model HW340 windrower currently marketed by New Holland North America, Inc., New Holland Pa., is propelled by hydraulic motors which drive the wheels. The equipment has no hydraulic brake system and does not have a brake pedal.